Footer Size for Load Calculator
Determine the minimum footing size needed to support a given load based on soil bearing capacity. Covers residential foundations and point loads.
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How It Works
Footing size is determined by the load divided by the soil bearing capacity. Typical presumptive soil bearing values: soft clay 1,500 psf, sandy soil 2,000 psf, compacted gravel 3,000 psf, bedrock 5,000+ psf. IRC minimum footing width for a one-story house on 2,000 psf soil is 12 inches. The footing depth should equal at least half the projection beyond the wall. Always have a soil test done for new construction to confirm bearing capacity.